Question: What event caused the end of West Germany as of 1990-10-2?
Paraphrase: On 1990-10-2, why did West Germany fall?
SPARQL (Wikidata): SELECT ?obj WHERE { wd:Q713750 p:P31 ?s . ?s ps:P31 ?obj . ?s pq:P582 ?x filter(contains(YEAR(?x),'1990')) }